PSI - Issue 62

Matteo Castellani et al. / Procedia Structural Integrity 62 (2024) 193–200 Matteo Castellani / Structural Integrity Procedia 00 (2019) 000 – 000

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1. Introduction The conservation of infrastructure is an essential pillar of the economic development of every country globally, as transportation networks and bridges form the backbone of connectivity and commercial efficiency within the country. Particularly in Italy, with its peninsular configuration and a heavy reliance on road transportation for its economy, careful management and maintenance of existing infrastructure have become crucial imperatives to ensure public safety, support commerce, and preserve national economic integrity. Italy's extremely diverse and extensive infrastructure stock has witnessed several tragic collapses in recent years, leading not only to considerable economic losses but also human fatalities. In 2020, the Italian Ministry of Infrastructure and Transport published the Guidelines for Risk Classification and Management, Safety Assessment, and Monitoring of Existing Bridges (hereinafter referred to as the Italian Guidelines), aiming to standardize bridge management, starting from assessing their risk and defective structural conditions to evaluating their structural performance, implementing monitoring systems, and more (Consiglio Superiore dei Lavori Pubblici, 2020). The Italian Guidelines command road concessionaires to conduct regular inspections, performed by qualified personnel, on all infrastructures annually. These resource-intensive activities aim to assess and constantly monitor the health of the structures. Planning for these activities also relies on the geometric characteristics of various structures. For older infrastructures, the absence of original project documentation is common, slowing down planning activities essential for understanding the structure, which can prove fatal in emergency scenarios. The need for a detailed understanding of bridge geometry and construction details is crucial for identifying potential issues at an early stage and planning preventive maintenance measures. Accurate knowledge of geometry and construction details provides a comprehensive overview of the structure, while the detection of structural anomalies enables the identification of cracks, defects, or any other issue that could compromise the safety and durability of bridges. A multidisciplinary perspective emerges as fundamental for effective bridge database management, a vital element in infrastructure conservation. The integration of advanced technologies, such as laser scanning and photogrammetry with the use of Unmanned Aerial Vehicles (UAVs), provides a comprehensive and detailed approach to capture vital information about the structural condition of bridges. This synergy of multidisciplinary tools allows for precise and high-precision data, essential for accurate assessment and optimal management of infrastructure. This article aims to explore the fundamental objectives related to infrastructure conservation, focusing on the application of a multidisciplinary approach that combines laser scanning and photogrammetry with UAVs for bridge database management. The adopted methodology, designed and applied to reinforced concrete box bridges, examines the planning of survey activities with different instruments, based on the joint use of these advanced tools to acquire high-resolution data, enabling an accurate assessment of the structural condition of bridges. 2. Methodology Based on the introductory arguments, the purpose of this paper is to propose a basic methodology that can facilitate the creation of a digital database of structures by managing entities, presenting itself as a fundamental aid for technicians responsible for inspections. Such a database allows for efficient planning of inspection phases, optimizing economic resources. Moreover, in the absence of design documentation, it provides a detailed understanding of the geometry of the infrastructure, facilitating the planning of special inspections. Furthermore, the creation of digital models at different time stages allows for a visual comparison of defects, enabling prioritization of inspections on the most critical infrastructures. The paper emphasizes the importance of the combined use of the most advanced sensing technologies to facilitate the creation of digital databases for managing authorities. The extensive use of drones in recent years has played a crucial role in the field of infrastructure, providing operators with an independent environment, reducing risks, and preventing disruptions or limitations to road traffic, thus avoiding potential economic damages and inconveniences. The combined use of drones and Terrestrial Laser Scanners (TLS) ensures the creation of extremely accurate digital models, even though TLS operations take more time. Although drone and TLS operations generate two different sets of data, their integration allows for a detailed and comprehensive representation of the bridge, as shown in Figure 1. This approach eliminates the need to fully or partially close road traffic, avoiding significant interruptions and ensuring